Difference between time stamp

Shell Programming and Scripting
1

Hi All
i have a file data like below format

A, B
2016-04-14 16:30:00,2016-04-14 16:31:17
2016-04-14 16:40:00,2016-04-14 16:41:10
2016-04-14 16:50:00,2016-04-14 16:50:41
2016-04-14 17:00:00,2016-04-14 17:00:35
2016-04-14 17:10:00,2016-04-14 17:11:48
2016-04-14 17:20:00,2016-04-14 17:20:37

i want output C (HH:MM:SS)=B-A
again i want max(C),min(C,avg(C)
i have tried so many formats i didn't get any result.
please help to me.
Regards,
Tara

2

What operating system are you using?

What shell are you using?

Exactly what output do you hope to produce from the sample input you provided in post #1 in this thread (in CODE tags, this time please)?

3

And, please show your failed attempts so we don't fall into the same pits.